The couple had argued in UK and European courts that they should not be extradited to the US because of concerns about their health and their possible treatment while in custody there.

At Heathrow Airport

By Neil BradfordBBC Look East

Today has been a day of confusion and speculation in this long running saga.

Paul and Sandra Dunham expected to be in a UK prison for 14 days - now they are just hours from extradition.

The couple believed they would be making a seven hour flight earlier, but they have simply swapped prison cells for the night.

It is understood they will be taken to Heathrow Airport on Thursday lunchtime and put directly on to a plane waiting for them on the tarmac for the 3,600 mile-flight.

Asked if enough consideration had been given to the Dunhams' mental health, Home Secretary Theresa May said: "The law now is that the Home Office, the home secretary, does not have the power to intervene.

"These are matters that go before the court and it's obviously for their legal representatives to decide whether they wish to take matters further before the court."

The allegations Mr Dunham faces centre on his time as chief executive and president of Pace, a US company manufacturing soldering irons for the electronics industry.

He was indicted on 13 counts of fraud and money laundering by a grand jury in Maryland in December 2011.

Mrs Dunham is accused of aiding and abetting him. The couple worked in the US between 1999 and 2009.

Authorities in the UK and the US have said they will not comment on the Dunham's case until the extradition has taken place.